From ae9c606ed228ea6a17ddde3a1e26451d02f51df7 Mon Sep 17 00:00:00 2001 From: Hitoshi Mitake Date: Mon, 15 Feb 2010 22:34:07 -0800 Subject: imap-send: support CRAM-MD5 authentication CRAM-MD5 authentication ought to be independent from SSL, but NO_OPENSSL build will not support this because the base64 and md5 code are used from the OpenSSL library in this implementation. Signed-off-by: Hitoshi Mitake Signed-off-by: Junio C Hamano --- imap-send.c | 146 +++++++++++++++++++++++++++++++++++++++++++++++++++++------- 1 file changed, 131 insertions(+), 15 deletions(-) (limited to 'imap-send.c') diff --git a/imap-send.c b/imap-send.c index ba72fa4b6..3ee25d964 100644 --- a/imap-send.c +++ b/imap-send.c @@ -27,6 +27,9 @@ #include "run-command.h" #ifdef NO_OPENSSL typedef void *SSL; +#else +#include +#include #endif struct store_conf { @@ -140,6 +143,20 @@ struct imap_server_conf { int use_ssl; int ssl_verify; int use_html; + char *auth_method; +}; + +static struct imap_server_conf server = { + NULL, /* name */ + NULL, /* tunnel */ + NULL, /* host */ + 0, /* port */ + NULL, /* user */ + NULL, /* pass */ + 0, /* use_ssl */ + 1, /* ssl_verify */ + 0, /* use_html */ + NULL, /* auth_method */ }; struct imap_store_conf { @@ -214,6 +231,7 @@ enum CAPABILITY { LITERALPLUS, NAMESPACE, STARTTLS, + AUTH_CRAM_MD5, }; static const char *cap_list[] = { @@ -222,6 +240,7 @@ static const char *cap_list[] = { "LITERAL+", "NAMESPACE", "STARTTLS", + "AUTH=CRAM-MD5", }; #define RESP_OK 0 @@ -949,6 +968,87 @@ static void imap_close_store(struct store *ctx) free(ctx); } +#ifndef NO_OPENSSL + +/* + * hexchar() and cram() functions are based on the code from the isync + * project (http://isync.sf.net/). + */ +static char hexchar(unsigned int b) +{ + return b < 10 ? '0' + b : 'a' + (b - 10); +} + +#define ENCODED_SIZE(n) (4*((n+2)/3)) +static char *cram(const char *challenge_64, const char *user, const char *pass) +{ + int i, resp_len, encoded_len, decoded_len; + HMAC_CTX hmac; + unsigned char hash[16]; + char hex[33]; + char *response, *response_64, *challenge; + + /* + * length of challenge_64 (i.e. base-64 encoded string) is a good + * enough upper bound for challenge (decoded result). + */ + encoded_len = strlen(challenge_64); + challenge = xmalloc(encoded_len); + decoded_len = EVP_DecodeBlock((unsigned char *)challenge, + (unsigned char *)challenge_64, encoded_len); + if (decoded_len < 0) + die("invalid challenge %s", challenge_64); + HMAC_Init(&hmac, (unsigned char *)pass, strlen(pass), EVP_md5()); + HMAC_Update(&hmac, (unsigned char *)challenge, decoded_len); + HMAC_Final(&hmac, hash, NULL); + HMAC_CTX_cleanup(&hmac); + + hex[32] = 0; + for (i = 0; i < 16; i++) { + hex[2 * i] = hexchar((hash[i] >> 4) & 0xf); + hex[2 * i + 1] = hexchar(hash[i] & 0xf); + } + + /* response: " " */ + resp_len = strlen(user) + 1 + strlen(hex) + 1; + response = xmalloc(resp_len); + sprintf(response, "%s %s", user, hex); + + response_64 = xmalloc(ENCODED_SIZE(resp_len) + 1); + encoded_len = EVP_EncodeBlock((unsigned char *)response_64, + (unsigned char *)response, resp_len); + if (encoded_len < 0) + die("EVP_EncodeBlock error"); + response_64[encoded_len] = '\0'; + return (char *)response_64; +} + +#else + +static char *cram(const char *challenge_64, const char *user, const char *pass) +{ + die("If you want to use CRAM-MD5 authenticate method, " + "you have to build git-imap-send with OpenSSL library."); +} + +#endif + +static int auth_cram_md5(struct imap_store *ctx, struct imap_cmd *cmd, const char *prompt) +{ + int ret; + char *response; + + response = cram(prompt, server.user, server.pass); + + ret = socket_write(&ctx->imap->buf.sock, response, strlen(response)); + if (ret != strlen(response)) + return error("IMAP error: sending response failed\n"); + + free(response); + + return 0; +} + static struct store *imap_open_store(struct imap_server_conf *srvc) { struct imap_store *ctx; @@ -1130,9 +1230,34 @@ static struct store *imap_open_store(struct imap_server_conf *srvc) if (!imap->buf.sock.ssl) imap_warn("*** IMAP Warning *** Password is being " "sent in the clear\n"); - if (imap_exec(ctx, NULL, "LOGIN \"%s\" \"%s\"", srvc->user, srvc->pass) != RESP_OK) { - fprintf(stderr, "IMAP error: LOGIN failed\n"); - goto bail; + + if (srvc->auth_method) { + struct imap_cmd_cb cb; + + if (!strcmp(srvc->auth_method, "CRAM-MD5")) { + if (!CAP(AUTH_CRAM_MD5)) { + fprintf(stderr, "You specified" + "CRAM-MD5 as authentication method, " + "but %s doesn't support it.\n", srvc->host); + goto bail; + } + /* CRAM-MD5 */ + + memset(&cb, 0, sizeof(cb)); + cb.cont = auth_cram_md5; + if (imap_exec(ctx, &cb, "AUTHENTICATE CRAM-MD5") != RESP_OK) { + fprintf(stderr, "IMAP error: AUTHENTICATE CRAM-MD5 failed\n"); + goto bail; + } + } else { + fprintf(stderr, "Unknown authentication method:%s\n", srvc->host); + goto bail; + } + } else { + if (imap_exec(ctx, NULL, "LOGIN \"%s\" \"%s\"", srvc->user, srvc->pass) != RESP_OK) { + fprintf(stderr, "IMAP error: LOGIN failed\n"); + goto bail; + } } } /* !preauth */ @@ -1310,18 +1435,6 @@ static int split_msg(struct msg_data *all_msgs, struct msg_data *msg, int *ofs) return 1; } -static struct imap_server_conf server = { - NULL, /* name */ - NULL, /* tunnel */ - NULL, /* host */ - 0, /* port */ - NULL, /* user */ - NULL, /* pass */ - 0, /* use_ssl */ - 1, /* ssl_verify */ - 0, /* use_html */ -}; - static char *imap_folder; static int git_imap_config(const char *key, const char *val, void *cb) @@ -1361,6 +1474,9 @@ static int git_imap_config(const char *key, const char *val, void *cb) server.port = git_config_int(key, val); else if (!strcmp("tunnel", key)) server.tunnel = xstrdup(val); + else if (!strcmp("authmethod", key)) + server.auth_method = xstrdup(val); + return 0; } -- cgit v1.2.1